A groundbreaking experiment that bombarded US high school students with inspiring text messages was found to be a success on all counts except one: it made no difference to how the students performed in school.

The students were given free mobile phones in return for receiving daily texts written by a trend-setting advertising agency, encouraging them to stay in school and study for exams.

Many of the students correctly answered quiz questions showing they had paid attention to the messages – but the nine-month-long randomised field study failed to find any improvement in the students' academic results or attendance.

Fryer concluded that while the daily diet of texts changed pupils' views about the value of education and caused them to say they were working harder in school, "there was no measurable increase in educational attainment or achievement".